FLOW SPIN ON REUSABLE HI FLOW OIL FILTERSFLO Spin On Oil Filter for Harley Davidson M8, Twin Cam, Evo & Buell Features Used by the Factory Harley Davidson Screamin Eagle Race Team Cleanable and Reusable Superior Filtration: 35 microns absolute rating (one pass test). This is much better than multiple pass rated paper filters, which are often lower micron filters. (Please Google for more research on why this is superior). Proven Aerospace, NASCAR, Indy, and Formula 1 Technology High Flow Rate